The present invention relates to a variable focal length camera, and more particularly to a control method and apparatus for close-up photography using a variable focal length lens having a telephoto close-up function and a standard close-up function.
There are known two types of variable focal length (vari-focal) lenses, including dual focal lenses and zoom lenses, that have a close-up or macro function, namely, a telephoto close-up type and a standard close-up type The telephoto close-up type is one in which the photographic state thereof is changeable from a telephoto state to a close-up state, while the standard close-up type is one in which the photographic state thereof is changeable from a standard state to a close-up state. The standard close-up type generally has a close-up magnification less than that of the telephoto close-up type, but has a nearer focusable distance.
Conventional variable focal length cameras have a telephoto close-up type vari-focal lens, so that changing over from a standard photography state to a close-up photography state cannot be quickly carried out because it is necessary to pass through a telephoto state. In a camera wherein a small stepping motor is used for focusing so as to lower the cost, since also the speed of focusing is low, it is impossible quickly to set the taking lens in an appropriate position. In order to speed up the taking lens positioning, it is possible to reduce the amount of lens movement. But, this would increase the nearest focusable distance in standard photography, for example, up to 0.8-1.0 m, so that the camera would not be focusable on a subject disposed nearer than this nearest focusable distance. Furthermore, conventional variable focal length cameras having a close-up function need a manual operation for changing over the taking lens to its close-up state, so that even when a principal subject is in focusable range for the close-up state, if the camera is set to a telephoto or standard size, the image of the subject will be out of focus.